The present invention relates to a multilayered ferromagnetic amorphous alloy film having both high saturation flux density and low coercive force and a magnetic head for magnetic recording and reproducing employing the multilayered ferromagnetic amorphous alloy film. More particularly, the invention,pertains to a magnetic head core material for high density magnetic recording and a magnetic head employing the same.
Ferromagnetic amorphous alloys do not have magnetocrystalline anisotropy on account of their amorphous properties and therefore display excellent characteristics as soft magnetic materials which make it possible to obtain high-permeability characteristics over a wide range of composition and to obtain a high saturation flux density higher than 10 KG. When a ferromagnetic metal film is employed as a magnetic head core material, a method has hitherto been adopted in which ferromagnetic metal films are laminated with an insulator, such as SiO.sub.2 or Al.sub.2 O.sub.3, interposed therebetween to form a multilayered ferromagnetic film, in order to ensure high permeability as far as a high-frequency region. However, when a multilayered ferromagnetic amorphous alloy film formed by laminating ferromagnetic amorphous alloy films with an insulator interposed therebetween is employed for a thin film magnetic head, edge portions of the multilayered film are not properly formed during a patterning process, which disadvantageously involves incapability of obtaining the dimensional accuracy required. Further, ply separation may undesirably occur since there is a large difference in thermal expansion coefficient between the insulator and the ferromagnetic amorphous alloy.
The following references are cited to show the state of the art; (i) Japanese Utility Model Laid-Open No. 58,613/1977, (ii) Japanese Patent Laid-Open No. 54,408/1977, and (iii) Japanese Patent Laid-Open No. 84,019/1980.